Dewitt c



(No Mael.)

D. C. MARKHAM.

y v BELL GRANK FOR MGWING MACHINES. 8

No. 325,950. PatentedSept. 8, 1885.

WITNBssEs: A Y INVBNTOB., d Maw v ATToRN UNITED STATES PATENT OFFICE.

DEWITT o. MARKHAM, or TovvANDA, rENNsYLvANIA, AssIGNoR To rrHE EUREKA MovvER COMPANY, or U'TicA, NEW YORK.

BELL-CRAN'K FOR MowlNG-MACHINES.

SPECIFICATION formingvpart of Letters Patent No. 325,950, dated September 8, 1885. Application fil-ed July 15, 1884. (No model.)

To all whom it may concern,.-

Be it known that I, DEWI'rr C. MARKHAM, a citizen of the United States, residing at To-l wanda, in the county of Bradford and State of Pennsylvania, have invented certain new and useful Improvements in Bell-Oranks for lVIow-` ing-Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same. I

In mowing-machines in which the knife is operated by an oscillating bell-crank-fas, for example, in the mowing-machine described in Letters Patent No. 304,837, granted to me September 9, 1884 there is atendency to raise the end of the knife as the bell-crank plays back and forth, and thus to get the knife out of shape and prevent its easy working. The end of the bell-crank where it is connected to the knife oscillates in the are of a circle, and is consequently raised at the limit of its inotion on each side above the plane of the knife. In order that the knife may work well, there should be little or no lost motion at the point Where it is connected with the lower arm of the bell-crank. It is, therefore, necessary that the knifehead,or that portion of the knife by which it is connected with the bell -'crank, should be so connected with the bell-crank as to be permitted no lateral movement; but as the' lower end of the bell-crank, where it is connected with the knife, constantly varies its horizontal plane as the bell-crank oscillates upon its inclined pivot, it is necessary that the knife-head be allowed vertical playin relation to the bell-crank-that is, since the knife cannot be rigidly attached to the bell-crank, the connection must be such that the knife may remain in the samehorizontal plane, While that of the bell-crank varies. Connection between the knife and bell-crank,which are designed to fulfill these requirements, fail more or less in practice, since it is impossible to make such a connection which shall always work perfectly and easily; and when the connection does not work perfectly it becomes more or less rigid, the result of which is, to a greater or less eX- tent, to cause the end of the knife to follow the circular path of the lower end of the bellcrank.

rIo obviate this defect is the object of this invention, and it is accomplished by forming the lower arm of the bell-crank with projections on each side, which come in contact with the knife when the bell-crank approaches its highest points and thus prevent the knife from being raised. f In the accompanying drawings,which illustrate myinvention and form part of this speci- 6o fication, Figure l is aperspective View of one i end of the cutter-bar of a mowing-machine,

showing the bell-crank and its relation to the cutter-bar. Fig. 2 is a direct front'view of the same, showing theimproved construction of the bell crank, and Fig. 3 is a View illustrating the operation of the improved bellcrank.

Like letters designate corresponding parts in all the figures.

7 A is the linger-bar, B the knife, C the shoe at Yone end of the cutter-bar, and D one of the leadi wheels,of amowing-machine; E,thebellcrank which is pivoted to the shoe at a, and F the lower end of the pitman which connects the bell-crank with the operating mechanism of the mowing-machine. The lower arm, G, of the bell-crank is made hollow and tubular, `and in it is inclosed a cylinder or piston barrel, M,

which receives the knife-post b and forms the 8o only connection between the knife and the bellcrank. As will be readily understood, the knife-post enters a radial aperture in the barrel M,and is free to move up and down therein. vThe arm G of the bell-crank is oscillated by the pitman in the same plane with the reciprocating motion of the knife. This lower arm is provided on opposite sides with projecting heels H -and I, which, when the bellcrank is in a central position, as shown in Fig. 9o

2,are both above the plane of 'the knife. When, now, the arm G of the bell-crank approaches its limit of motion to the right, as indicated at the right in Fig. 3, the h eel H is depressed,

and, coming in contact with the knife, prevents it from being raised; and when the arm approaches its limit of motion to the left, as indicated at the left in Fig. 3, the vheel I is depressed, and, coming in contact 'with the knife, prevents it from beingraised 0u that roo side.

The heel His made longer and of somewhat 2 sses nation with a bell-orenk,whioh imparts ieeip-- ro meeting motion to said knife, said heli-omnk being provided with heels on each side of its lower arm, substantially as and for the purpose seb forth.

In testimony WhereofI affix my signature in presence of two Witnesses.

DE WITT G. MARKHABI.

Vitnesses:

M. W. Ross, JNO. E. FOX. 

